In a load driving circuit that drives a load using a direct current (DC) power source, for example, a metal-oxide-semiconductor field-effect transistor (MOSFET) that controls a current conduction has been conventionally used. In such a load driving circuit, when the DC power source is reverse-connected, that is, connected in reverse direction, there is a possibility that an unexpected current flows to the load through a parasitic diode of the MOSFET, and the MOSFET and the load are thermally destroyed. In JP 2014-50032 A, a load driving circuit is connected to a reverse-connection protecting circuit that can interrupt a current when a DC power source is reverse-connected.